Production of complex metal compounds of ortho-hydroxyazo dyestuffs



.gc ofi of the alkyl radicle takes place.

Patented Oct. 30, I934 umrso fsmr PRODUCTION OF '1,97s,ss0

COMBLEX METAL COM- POUNDS or on'rno-nynnoxyazo DYE- Fritz Lange and HansKrzikalla; Ludwigshafencn the-Rhme, Germany, assignors to General AmlmeWorks, Inc;, New York, N. Y., a corpora- -;tion of Delaware b Drawing.Application Amine, 1933, Serial:

' No. 667,497. In Germany May 10,1932

6 Claims. .(Cl. 260-12)" The present invention relates to a new: pita;ess of producing complex .metalfjcompounds,

especially complex chromium compounds of ortho-hydroxyazo-dyestuffs.

tion of complex metal compounds of ortho-hydroxyazo-dyestufis hasalready been proposed in the Patent No. 1,765,680 which consists intreating azo dyestuffs containing alkoxy groups in lo ortho-position tothe azo group with metal com- "pounds capable of forming complex metalcompounds of dyestuffs under conditions under which a splitting off ofthe alkyl radicles takes place.

We have now found that especially valuable complex chromium compounds ofortho-hydroxyazo-dyestufis are obtained according to the said process byemploying chromium sulphates under conditions under which a splittingSplitting off the alkyl groups is advantageously effected by heating thedyestuffs with chromium sulphates in the presence of water attemperatures above 100 0., preferably between 110 and 25;-150 C.; themost suitable range of temperature is between 130 and 140 C. Accordinglythe reaction is preferably carried out under elevated pressure. The azodyestufis containing chromium obtained according to this invention s g-yield specially pure and even dyeings having excellent fastness tolight.

Neutral, acid orbasic chromium sulphates, or chromium sulphate liquors,as for example those obtained as by-products in processes in fist-Whichbichromates or chromates are used as oxidizing agents, are suitable forthe introduction of chromium.

The process according to the present invention permits of the productionof valuable dyestuffs in a relatively cheap manner; no volatile acidsare formed during the process which might injure parts of the apparatusand which might necessitate certain precautions to avoid injury tohealth. The process may be carried out in 45,. vessels lined with lead.

The following examples will further illustrate how the said inventionmay be carried out in practice, but the invention is not restricted tothese examples. The parts are by weight.

. Example 1 52 parts of the azo dyestuff derived from diazotized4-chlor-2-amino-l-methoxybenzene and2-hydroxynaphthalene-6,8-disulphonic acid are 5 5 dissolved in 300 partsof water and heated for about 3 hoursat from 130'?" to 135 C. in a stirring, autoclave lined with lead with a solution containing 12 parts ofchromium oxide, 24 parts i of sulphuric acidof 66 B. strength and 100:5; A process for the manufacture and producparts ofwater. The complexchromium compound formed separates inpart spontaneously. 'I'hepartremaining dissolved is precipitated by the addition of hydrochloric orsulphuric acid. The chromium compound obtained yields pure violetdyeings having excellent properties as regards fastness on wool.

The solution of a basic chromium sulphate, containing for example 12parts of chromium oxide and only 20 parts of sulphuric acid of 66 B.strength, may also be employed for the introduction of chromium.

Example 2 52 parts of the azo-dyestuff derived from diazotized4-chlor-2-amino-l-methoxybenzene and1-hydroxynaphthalene-3,8-disulphonic acid are dissolved in 800 parts ofwater and heated for about 3 hours at from 130 to 140 C. in a stirringautoclave lined with lead with a solution containing 12 parts ofchromium oxide, 28 parts of sulphuric acid of 66 B. strength and 200parts of water. The chromium compound formed is then salted out in theusual manner. It yields blue dyeing on wool and silk.

Example 3 54 parts of the dyestuff obtainable by coupling diazotized5-nitro-4-methyl2-amino-1-methoxybenzene withl-hydroxynaphthalene-4,8-disulphonic acid are dissolved in about 250parts of water and heated with an aqueous solution of chromium sulphate(consisting of 100 parts of water, 19 parts of sulphuric acid of 66 B.and 12 parts of chromium oxide) in a stirring autoclave lined with lead.The temperature is maintained for 1 hour at 125 C., for another hour at130 C. and then for 1 hour at 135 C. The chromium compound thus formedis salted out by means of sodium chloride in the usual manner. It dyeswool and silk deep navy blue shades. 100

Example 4 54 parts of the dyestuff obtainable by coupling diazotized1-methoy-2-amino-4-methyl-5-nitrobenzene with2-hydroxynaphthalene-6,8-disul- 5 phonic acid are dissolved in about 250parts of water and heated with an aqueous solution of chromium sulphate(consisting of 100 parts of water, 19 parts of sulphuric acid of 66 B.and

12 parts of chromium oxide) in a stirring autoclave lined with lead. Thetemperature is maintained for 1 hour at 125 C., for another hour at 130C. and then for 1 hour at 135 C. The chromium compound thus formed issalted out by means of sodium chloride in the usual manner. It dyes Wooland silk blue violet shades. A

What we claim is:--

1. The process of producing complex chromium! compounds ofortho-hydroxyazo-dyestufis, which comprises treating an azo-dyestuficontaining an alkoxy group in ortho-position to the azo group, with asulphate of chromium, in theppresence 1 comprises treating theazo-dyestufi obtainable by of water at temperatures above 100 C. 1

2. The process'of producing complexchr'o: mium compounds ofortho-hydro-xyazo-dyestufis, which comprises treating a an azo-dyestufficontaining-an alkoxy group in ortho-positionto the azo group, with asulphate of chromiumfin the presence of water at temperaturesabo-ve100'C.-

under elevated pressure.

, 3. The'processo producing'complex chromium compounds of 'orthohydroxyazmdyestuffs, which comprises treating'a'n 'azo-dyestufiobtainable by the presence of water at temperatures above 100 C.

4. The processof producing complex chromium compounds of orthohydroxyazo-dyestuffs, which comprises treating the azo-dyestuffobtainable by coupling diazotized 4-chlor-2-amino-1-methoxybenzene with2-hydroxynaphthalene-6,S-disulphonic acid, with a sulphate of chromium,in

'the presence of water at temperatures above 5. The process of producingcomplex chromium compounds of:ortho-hydroxyazo dyestuffs, which couplingdiazotized l-chlor-Z-amino-l-methoxybenzene with 1hydroxynaphthalene-3,8-disu1- 6. The process of producing complexchromium compounds of ortho-hydroxyazo-dyestufis, which comprisestreating the azo-dyestuff obtainable by coupling5-nitro4-inethyl-2-amiho-1-methoxy- FRITZ LANGE. HANS KRZIKALLA.

